Electrosurgical devices

ABSTRACT

In various embodiments, a surgical instrument is disclosed. In one embodiment, the surgical instrument comprises a handle, a shaft assembly extending distally from the handle; and an end effector coupled to a distal end of the shaft assembly. The end effector comprises a jaw assembly having a proximal end and a distal end. The jaw assembly comprises a moveable jaw member and a fixed jaw member. The moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member. In the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.14/075,839, now U.S. Patent Application Publication No. 2015/01333921,filed concurrently with the present application and incorporated byreference herein in its entirety.

BACKGROUND

The present disclosure is related generally to electrosurgical deviceswith various mechanisms for clamping and treating tissue. In particular,the present disclosure is related to electrosurgical devices withvarious mechanisms for controlling a curved end effector.

While several devices have been made and used, it is believed that noone prior to the inventors has made or used the device described in theappended claims.

SUMMARY

In various embodiments, a surgical instrument is disclosed. In oneembodiment, the surgical instrument comprises a handle, a shaft assemblyextending distally from the handle; and an end effector coupled to adistal end of the shaft assembly. The end effector comprises a jawassembly having a proximal end and a distal end. The jaw assemblycomprises a moveable jaw member and a fixed jaw member. The moveable jawmember is pivotably moveable between an open position and a closedposition with respect to the fixed jaw member. In the closed position,the jaw assembly defines a radius of curvature and a smooth taper fromthe proximal end to the distal end.

In various embodiments, a surgical end effector is disclosed. In oneembodiment, a surgical end effector comprises a jaw assembly having aproximal end and a distal end. The jaw assembly comprises a moveable jawmember, a fixed jaw member, and a pivot connection coupling the moveablejaw member and the fixed jaw member. The moveable jaw member ispivotably moveable between an open position and a closed position withrespect to the fixed jaw member. In the closed position, the jawassembly defines a radius of curvature and a smooth taper from theproximal end to the distal end

In various embodiments, a surgical instrument is disclosed. In oneembodiment, the surgical instrument comprises a handle, a shaft assemblyextending distally from the handle, and an end effector coupled to adistal end of the shaft assembly. The shaft assembly comprises a leverarm extending distally therethrough. The end effector comprises a jawassembly having a proximal end and a distal end. The jaw assemblycomprises a moveable jaw member and a fixed jaw member. The moveable jawmember is pivotably moveable between an open position and a closedposition with respect to the fixed jaw member. The lever arm isasymmetrically coupled to the moveable jaw member on a first side of acentral axis of the shaft assembly. A pivot connection between themoveable jaw member and the fixed jaw member is offset to the first sideof the central axis of the shaft assembly. In the closed position, thejaw assembly defines a radius of curvature and a smooth taper from theproximal end to the distal end.

DRAWINGS

The novel features of the embodiments described herein are set forthwith particularity in the appended claims. The embodiments, however,both as to organization and methods of operation may be betterunderstood by reference to the following description, taken inconjunction with the accompanying drawings as follows.

FIG. 1 illustrates one embodiment of an electrosurgical instrument.

FIG. 2 illustrates a side-perspective of the electrosurgical instrumentof FIG. 1.

FIG. 3 illustrates a side-view of the electrosurgical instrument of FIG.1.

FIG. 4 illustrates a perspective view of the electrosurgical instrumentof FIG. 1 with a left handle housing removed.

FIG. 5 illustrates an exploded view of the electrosurgical instrument ofFIG. 1.

FIG. 6 illustrates a side view of the electrosurgical instrument FIG. 1comprising a jaw closure system in the handle assembly.

FIG. 7 illustrates the electrosurgical instrument of FIG. 6 with the jawclosure system in a partially-closed position.

FIG. 8 illustrates a firing mechanism lock-bar interfaced with cuttingmember firing mechanism.

FIG. 9 illustrates a closure trigger rotated sufficiently to disengage alock bar from a rack unlock block.

FIG. 10 illustrates the firing mechanism lock-bar of FIG. 8 in anunlocked position.

FIG. 11 illustrates one embodiment of a jaw position sensor.

FIG. 12 illustrates one embodiment of a jaw position sensor comprisingan adjustment screw lock spring.

FIG. 13 illustrates one embodiment of a jaw position sensor.

FIG. 14 illustrates one embodiment of a jaw position sensor mounted in ahandle assembly.

FIG. 15 illustrates one embodiment of the electrosurgical instrument ofFIG. 4 with the closure trigger fully actuated.

FIG. 16 illustrates the electrosurgical instrument of FIG. 4 with aclosure trigger lock engaged.

FIG. 17 illustrates the electrosurgical instrument of FIG. 16 with afiring trigger in an actuated position.

FIG. 18 illustrates one embodiment of a yoke of a jaw closure systemcoupled to a return stroke dampener.

FIG. 19 illustrates one embodiment of return stroke dampener.

FIG. 20A illustrates the interface between a yoke and a return strokedampener when the jaws of an end effector are in a closed position.

FIG. 20B illustrates the interface between the yoke and the returnstroke dampener when the jaws of the end effector transition to an openposition.

FIG. 21 illustrates the electrosurgical instrument of FIG. 4 with theclosure trigger lock released and the closure trigger in a releasedposition.

FIG. 22 illustrates one embodiment of a rack spring washer.

FIG. 23 illustrates one embodiment of a jaw closure spring stop.

FIG. 24 illustrates one embodiment of an electrical energy systemcomprising an energy button, a source cable, and a return cable.

FIG. 25 illustrates one embodiment of an electrosurgical instrumentcomprising a pre-compressed jaw closure spring.

FIG. 26 illustrates one embodiment of an electrosurgical instrumentcomprising a top-mounted knife firing gear and rack.

FIGS. 27A and 27B illustrate one embodiment of an electrosurgical endeffector comprising a curved shape.

FIG. 28 illustrates one embodiment of the electrosurgical end effectorof FIGS. 27A-27B comprising an off-set jaw closure actuator.

FIG. 29 illustrates one embodiment of an electrosurgical end effectorcomprising a first jaw member and a second jaw member having a smoothtaper, curved shape.

FIG. 30 illustrates one embodiment of the electrosurgical end effectorof FIG. 29 in a closed position.

FIG. 31 illustrates one embodiment of a lower jaw of the electrosurgicalend effector of FIGS. 29-30 comprising a curved longitudinal cuttingmember slot.

FIG. 32 shows a graph illustrating the mechanical advantage of theclosure trigger at various trigger angles.

FIG. 33 shows a graph illustrating force delivered by the jaws when notissue is located within the jaws.

FIG. 34 shows a graph illustrating force delivered by the jaws when atissue section is located within the jaws.

FIG. 35 shows a graph illustrating the dampener effect on a return loadprovided by a return stroke dampener.

DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols and reference characters typically identify similarcomponents throughout the several views, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, drawings, and claims are not meant to be limiting. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the scope of the subject matter presented here.

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

Before explaining the various embodiments of the surgical devices withclose quarter articulation features in detail, it should be noted thatthe various embodiments disclosed herein are not limited in theirapplication or use to the details of construction and arrangement ofparts illustrated in the accompanying drawings and description. Rather,the disclosed embodiments may be positioned or incorporated in otherembodiments, variations and modifications thereof, and may be practicedor carried out in various ways. Accordingly, embodiments of the surgicaldevices with close quarter articulation features disclosed herein areillustrative in nature and are not meant to limit the scope orapplication thereof. Furthermore, unless otherwise indicated, the termsand expressions employed herein have been chosen for the purpose ofdescribing the embodiments for the convenience of the reader and are notto limit the scope thereof. In addition, it should be understood thatany one or more of the disclosed embodiments, expressions ofembodiments, and/or examples thereof, can be combined with any one ormore of the other disclosed embodiments, expressions of embodiments,and/or examples thereof, without limitation.

Also, in the following description, it is to be understood that termssuch as front, back, inside, outside, top, bottom and the like are wordsof convenience and are not to be construed as limiting terms.Terminology used herein is not meant to be limiting insofar as devicesdescribed herein, or portions thereof, may be attached or utilized inother orientations. The various embodiments will be described in moredetail with reference to the drawings.

Turning now to the figures, FIG. 1 illustrates one embodiment of anelectrosurgical instrument 2. The electrosurgical instrument 2 comprisesa two-trigger clamp and cut mechanism. The electrosurgical instrument 2comprises a handle assembly 4, a shaft assembly 12 coupled to a distalend of the handle assembly 4, and an end effector 10 coupled to thedistal end of the shaft assembly 12. The handle assembly 4 is configuredas a pistol grip and comprises left and right handle housing shrouds 6a, 6 b, a closure trigger 8, a pistol-grip handle 14, a firing trigger16, an energy button 18, and a rotatable shaft knob 20. An electricalcable 21 enters the handle assembly 4 at a proximal end.

The shaft assembly 12 comprises a jaw actuator, a cutting memberactuator, and an outer sheath 23. The jaw actuator is operativelycoupled to the closure trigger 8 of the handle assembly 4. In someembodiments, the outer sheath 23 comprises the jaw actuator. The cuttingmember actuator is operatively coupled to the firing trigger 14 of thehandle assembly 4. The outer sheath 23 comprises one or more contactelectrodes on the distal end configured to interface with the endeffector 10. The one or more contact electrodes are operatively coupledto the energy button 18 and an energy source (not shown).

The energy source may be suitable for therapeutic tissue treatment,tissue cauterization/sealing, as well as sub-therapeutic treatment andmeasurement. The energy button 18 controls the delivery of energy to theelectrode. A detailed explanation of each of these control elements isprovided herein below. As used throughout this disclosure, a buttonrefers to a switch mechanism for controlling some aspect of a machine ora process. The buttons may be made out of a hard material such asusually plastic or metal. The surface may be formed or shaped toaccommodate the human finger or hand, so as to be easily depressed orpushed. Buttons can be most often biased switches, though even manyun-biased buttons (due to their physical nature) require a spring toreturn to their un-pushed state. Terms for the “pushing” of the button,may include press, depress, mash, and punch.

In some embodiments, an end effector 10 is coupled to the distal end ofthe shaft assembly 12. The end effector 10 comprises a first jaw member22 a and a second jaw member 22 b. The first jaw member 22 a ispivotably coupled to the second jaw member 22 b. The first jaw member 22a is pivotally moveable with respect to the second jaw member 22 b tograsp tissue therebetween. In some embodiments, the second jaw member 22b is fixed. In other embodiments, the first jaw member 22 a and thesecond jaw member 22 b are pivotally movable. The end effector 10comprises at least one electrode 92. The electrode 92 is configured todelivery energy. Energy delivered by the electrode 92 may comprise, forexample, radiofrequency (RF) energy, sub-therapeutic RF energy,ultrasonic energy, and/or other suitable forms of energy. In someembodiments, a cutting member (not shown) is receivable within alongitudinal slot defined by the first jaw member 22 a and/or the secondjaw member 22 b. The cutting member is configured to cut tissue graspedbetween the first jaw member 22 a and the second jaw member 22 b. Insome embodiments, the cutting member comprises an electrode fordelivering energy, such as, for example, RF and/or ultrasonic energy.

FIG. 2 illustrates a side perspective view of the electrosurgicalinstrument 2 illustrated in FIG. 1. FIG. 2 illustrates the right handlehousing 6 b. The energy button 18 extends through the handle assembly 4and is accessible on both sides of the handle assembly 4. The closuretrigger 8, the firing trigger 14, and the energy button 18 comprise anergonomic design. In some embodiments, the handle assembly 14 is thinnernear the energy button 18 to allow ease of access to the energy button18 by a clinician. In some embodiments, the energy button 18 is disposedon either the left handle housing 6 a or the right handle housing 6 b.FIG. 3 illustrates a side view of the electrosurgical instrument 2 andthe right handle housing 6 b.

FIG. 4 illustrates one embodiment of the surgical instrument 2 of FIG. 1with the left handle housing 6 a removed. The handle assembly 4comprises a plurality of components for actuating the surgicalinstrument 2, such as, for example, mechanisms for affecting closure ofthe jaws 22 a, 22 b of the end effector 10, deploying a cutting memberwithin the end effector 10, and/or delivering energy to the electrode 92coupled to the end effector 10. A closure trigger 8 is configured totransition the jaws 22 a, 22 b from an open position to a closedposition. The closure trigger 8 is connected to a clamp arm 24. Theclamp arm 24 couples the closure trigger 8 to a yoke 26. When theclosure trigger 8 is actuated towards the pistol grip handle 14, theyoke 26 moves proximally and compresses a clamp spring 28. Compressionof the clamp spring 28 retracts a jaw actuator, such as, for example,the outer sheath 23, to transition the first jaw member 22 a of the endeffector 10 from an open position to a closed position. In theillustrated embodiment, the clamp spring 28 comprises an uncompressedspring. In some embodiments, a partially pre-compressed spring may beused (see FIG. 25).

A firing trigger 16 is configured to deploy a cutting member within theend effector 10. The firing trigger 16 is operatively coupled to acompound gear 42. The compound gear 42 interfaces with a rack 44. Therack 44 is coupled to a firing actuator (not shown). When the firingtrigger 16 is actuated, the compound gear 42 rotates and moves the rack44 distally. The distal movement of the rack 44 causes distal movementof the firing actuator and deployment of the cutting member within theend effector 10. The cutting member is deployed from the proximal end ofthe end effector 10 to the distal end. In one embodiment, the firingtrigger 16 comprises a high pivot to provide a linear feel duringactuation of the firing trigger 16. The linear feel provides increasedcontrol and comfort to a clinician actuating the firing trigger 16.

In some embodiments, the rack 44 comprises a lock mechanism. In theillustrated embodiment, the rack 44 comprises a rack unlock block 40.The rack unlock block 40 interfaces with a lock arm 38 to preventactuation of the cutting member firing switch 16 prior to actuation ofthe closure trigger 8. When the closure trigger 8 is in an openposition, the lock arm 38 interfaces with the rack unlock block 40 tolock the rack 44 and prevent actuation of the firing trigger 16. Whenthe closure trigger 8 is actuated, the yoke 26 raises the lock arm 38away from the rack unlock block 40. When the closure trigger 8 issufficiently actuated, corresponding to the jaws 22 a, 22 b of the endeffector 10 being in a sufficiently closed position to prevent thecutting member from existing a slot in the jaws 22 a, 22 b, the lock arm38 is decoupled from the rack unlock block 40, allowing actuation of thefiring trigger 16.

FIG. 5 illustrates an exploded view of the electrosurgical instrument 2.As shown in FIG. 5, the handle assembly 4 comprises a left handlehousing 6 a and a right handle housing 6 b. The handle assembly 4comprises a closure trigger 8, a firing trigger 16, and an energy button18. A clamp arm 24 is coupled to the jaw closure trigger 8 and a yoke 26by a plurality of pins 52. A mil max connector 53 is located at aproximal end of the handle assembly 4 to couple to an energy source (notshown). Although the illustrated embodiments comprise a surgicalinstrument 2 coupled to an external energy source, those skilled in theart will recognize that the energy source and/or one or more drivecircuits may be located within the handle assembly 4. For example, inone embodiments, a battery and a RF generation circuit may be mounted inthe handle assembly 4 and coupled to the energy button 18. In someembodiments, a jaw position sensor 34 is mounted in the handle assembly4 to indicate when the jaws 22 a, 22 b of the end effector 10 haveclosed beyond a predetermined position. A screw lock spring 36 ismounted to the jaw position sensor 34 to prevent accidental adjustmentof the jaw position sensor 34. A control board 48 is mounted in thehandle assembly 4.

FIG. 6 illustrates a side perspective of the handle assembly 4comprising a jaw closure mechanism in the handle assembly 4. The closuretrigger 8 is illustrated in an initial position corresponding to an openposition of the jaws 22 a, 22 b. In operation, a clinician actuates theclosure trigger 8 to transition the jaws 22 a, 22 b to a closedposition. FIG. 7 illustrates the closure trigger 8 in a partiallyactuated position. As shown in FIG. 7, as the closure trigger 8 isrotated proximally towards the pistol-grip handle 14, the clamp arm 24moves the yoke 26 in a proximal direction to compress the clamp spring28. Compression of the clamp spring 28 causes the jaws 22 a, 22 b totransition to a closed position and applies a force to tissue graspedbetween the jaws 22 a, 22 b. For example, in some embodiments, theclosure trigger 8 position illustrated in FIG. 7 corresponds to a fullclosure of the jaws 22 a, 22 b. Additional actuation of the closuretrigger 8 increases the force applied by the jaws 22 a, 22 b to a tissuesection grasped therebetween. In other embodiments, full closure of thejaws 22 a, 22 b occurs when the closure trigger 8 is fully actuated. Ahole 19 in the closure trigger 8 allows the closure trigger 8 to beactuated without interfering with the energy button 18. In someembodiments, the hole 19 is covered by the left and right handlehousings 6 a, 6 b.

FIG. 8 illustrates a firing trigger lock mechanism 33. A lock arm 38interfaces with a rack unlock block 40 to prevent actuation of thefiring trigger 16 prior to closure of the jaws 22 a, 22 b. The firingtrigger lock mechanism 33 is unlocked through actuation of the closuretrigger 8. The yoke 26 is coupled to an unlock bar 41. When the yoke 26is moved distally through actuation of the closure trigger 8, the lockbar 41 lifts the lock arm 38 vertically away from the rack unlock block40. When the lock arm 38 has been lifted a sufficient distance, the rack44 is allowed to move distally and the firing trigger 16 is actuatableto deploy the cutting member within the end effector 10. FIGS. 9 and 10illustrate the handle assembly 4 of the surgical instrument 2 with thejaw clamping trigger 8 sufficiently compressed to release the lock arm38 from the rack unlock block 40. As can be seen in FIG. 9, the lock arm38 is lifted a sufficient distance to allow actuation of the firingtrigger 16 prior to full rotation of the closure trigger 8. The firingtrigger 16 is unlocked when the jaws 22 a, 22 b are sufficiently closedsuch that the cutting member cannot skip out of a slot formed in the endeffector 10. For example, in some embodiments, the lock arm 38 isreleased when the closure trigger 8 is compressed about 8 degrees,corresponding to jaw opening of about 2.5 degrees. In other embodiments,the lock arm 38 may be released at a lower or higher degree of rotationof the closure trigger 8.

In some embodiments, a lock spring 64 is coupled to the lock arm 38 toapply a biasing force to the lock arm 38. The biasing force biases thelock arm 38 towards the rack unlock block 40 and maintains the lock arm38 in contact with the rack unlock block 40 until the closure trigger 8has been sufficiently actuated. When the closure trigger 8 is releasedand the yoke 26 returns to a rest position, the lock spring 64 biasesthe lock arm 38 back into a locked configuration with the rack unlockblock 40.

FIG. 10 illustrates the lock arm 38 in an unlocked position. In theunlocked position, a clinician may actuate the firing trigger 16 todrive the rack 44 distally and deploy the cutting member within the endeffector 10. In some embodiments, a jaw position sensor 34 is configuredto indicate when the jaws 22 a, 22 b are sufficiently closed to allowdeployment of the cutting member. In some embodiments, the jaw positionsensor 34 comprises a bypass switch. In other embodiments, other typesof switches may be used, such as, for example, normally open, normallyclosed, and/or other switch types.

FIG. 11 illustrates one embodiment of a jaw position sensor 34. The jawposition sensor 34 comprises an adjustable contact 77. The adjustablecontact 77 is mechanically adjustable to adjust the jaw sense activationpoint of the jaw position sensor 34. The contact 77 is adjusted byrotating a screw 76 coupled to the jaw position sensor 34. Rotation ofthe screw 76 increases or decreases (depending on the direction ofrotation) the necessary height of the lock arm 38, corresponding to aspecific rotation of the closure trigger 8, required to activate the jawposition sensor 34. In some embodiments, such as the embodimentillustrated in FIG. 12, a screw lock spring 36 is coupled to the screw76 to prevent accidental adjustment of the contact 77. In order toadjust the contact 77 in the embodiment illustrated in FIG. 12, thescrew lock spring 36 must be depressed prior to rotation of the screw76. The screw lock spring 36 is released after adjustment of the screw76 to lock the screw 76 in place. In some embodiments, the screw 76comprises a locking thread. Activation of the jaw position sensor 34 maycorrespond to, for example, a distance of about 0.01 inches between thefirst jaw 22 a and the second jaw 22 b.

FIG. 13 illustrates one embodiment of a jaw position sensor 134. The jawposition sensor 134 comprises a switch 170. When the contact 177 of theswitch 170 is depressed by the lock bar 41, an electrical connectionwithin the switch 170 is opened. The break in the electrical connectionof the switch 170 is detected by a two-position connection header 172.The connection header 172 is coupled to, for example, a control board38. A connected receptacle 174 couples the connection header 172 to thehandle assembly 4. FIG. 14 illustrates the jaw sensor 34 mounted in thehandle assembly 4. The handle assembly 4 comprises a plurality of accessholes 79 to allow a clinician to depress the screw lock spring 36 and torotate the screw 76 to adjust the contact 77.

FIG. 15 illustrates one embodiment of the handle assembly 4 with theclosure trigger 8 fully actuated. When the closure trigger 8 is fullyactuated, the yoke 26 compresses the clamp spring 28 to a maximumcompression, corresponding to a maximum force applied by the jaws 22 a,22 b. In some embodiments, the jaws 22 a, 22 b may be configured tomaintain a minimal spacing therebetween to prevent damage to componentsof the surgical instrument 2 and/or the tissue section. In otherembodiments, the maximum compression of the clamp spring 28 correspondsto a fully closed position of the jaws 22 a, 22 b. In some embodiments,full actuation of the closure trigger 8 corresponds to a rotation ofabout 30 degrees. When the closure trigger 8 is fully rotated againstthe pistol-grip handle 14, a closure trigger lock 46 is engaged tomaintain the closure trigger 8 in a rotated position and thereforemaintain the jaws 22 a, 22 b in a closed position. As shown in FIG. 15,the hole 19 in the closure trigger 8 allows the closure trigger 8 to befully rotated against the pistol-grip handle 14 without interfering withthe energy button 18. Once the trigger lock 46 has been engaged, theclinician may release the closure trigger 8 and the trigger lock 46maintains the closure trigger 8 in a closed position, as illustrated inFIG. 16.

As shown in FIG. 16, the trigger lock 46 maintains the closure trigger 8in a less than fully retracted position to prevent damage to componentsof the surgical instrument 2 due to over application of force to thejaws 22 a, 22 b. The trigger lock 46 maintains the closure trigger 8 ina sufficiently rotated position to release the lock arm 38 from the rackunlock block 40 and to engage the jaw position sensor 34. For example,in the illustrated embodiment, the trigger lock 46 maintains the closuretrigger 8 at a rotation of about 28 degrees. With the closure trigger 8in a locked position, the clinician may actuate the firing trigger 16 todeploy the cutting member within the end effector 10. In someembodiments, the clinician may actuate the energy button 18 to deliverenergy to a tissue section grasped between the jaws 22 a, 22 b prior toor simultaneously with, deployment of the cutting member.

In various embodiments, the closure trigger 8 provides a mechanicaladvantage in transferring force from the closure trigger 8 to the jaws22 a, 22 b. FIG. 32 is a chart 700 illustrating the mechanical advantage704 of the closure trigger 8 at various trigger angles 702. As shown inFIG. 32, as the angle of the closure trigger 8 increases, for example,by actuating the closure trigger 8 towards the pistol-grip handle 14,the mechanical advantage 704 delivered by the clamp spring 28 to thejaws 22 a, 22 b increases. FIGS. 33 and 34 illustrate the force providedby the jaws 22 a, 22 b as the closure trigger 8 is rotated towards thepistol-grip handle 14. FIG. 33 illustrates force 806 delivered by thejaws 22 a, 22 b when no tissue is located within the jaws 22 a, 22 b.FIG. 34 illustrates the force 906 delivered by the jaws 22 a, 22 b whena tissue of about 3 mm thickness is located between the jaws 22 a, 22 b.

As illustrated in FIG. 16, the firing trigger 16 is coupled to acompound gear 42 interfaced with a rack 44. The rack 44 is mechanicallycoupled to a firing actuator (not shown) configured to deploy thecutting member distally within the end effector 10. Rotation of thefiring trigger 16 proximally towards the handle assembly 4 causes therack 44 to advance distally within the handle assembly 4 and drive thecutting member within the end effector 10. FIG. 17 illustrates thehandle assembly 4 with the firing trigger 16 in an actuated position.The compound gear 42 has advanced the rack 44 distally, corresponding tothe cutting member being located at a distal most position within theend effector 10. Advancement of the rack 44 in a distal directioncompresses a spring washer 58. When the clinician releases the firingtrigger 16, the spring washer forces the rack 44 in a proximaldirection, withdrawing the cutting member from the end effector 10. Thefiring trigger 16 comprises a mechanical advantage that adjusts theforce applied by the cutting member with respect to the force applied tothe firing trigger 16. For example, in one embodiment, the firingtrigger 16 comprises a mechanical advantage of 0.6, such that one poundof force applied to the firing trigger 16 corresponds to 0.6 pounds offorce applied by the cutting member to a tissue section grasped withinthe end effector 10. In some embodiments, the firing trigger 16comprises a maximum rotation corresponding to the cutting member beinglocated at a distal-most portion of the end effector 10. For example,the firing trigger 16 may rotate about nineteen degrees to fully deploythe cutting member within the end effector 10. In some embodiments, thehandle assembly 4 comprises a rack-biasing spring 47 configured to biasthe rack in an proximal position. The closure trigger lock 46 isreleased to open the jaws 22 a, 22 b and release tissue grasped therein.

FIG. 18 illustrates one embodiment of a return stroke dampener 32coupled to the yoke 26 to reduce the force of the return stroke of theclamp spring 28. The return stroke dampener 32 dampens the return strokeof the yoke 26 when the closure trigger 8 is released. FIG. 19illustrates one embodiment of a return stroke dampener 32. FIGS. 20A and20B illustrate an interface between the yoke 26 and the return strokedampener 32. The return stroke dampener 32 comprises a toggle arm 78 anda dampening spring 76. The yoke 26 comprises a dampener interface pin79. When the yoke 26 moves distally, for example, when the jaws 22 a, 22b are released and the closure trigger 8 returns to an unactuatedposition, the interface pin 79 forces the toggle arm 78 down,compressing the dampening spring 76 and reducing the load from theclosure spring 28 on the closure trigger 8. Once the interface pin 79pushes the toggle arm 78 close to over center, the load on the yoke pin79 goes almost to zero such that the dampener effect is eliminated forthe remainder of the stroke. The return stroke dampener 32 reduces theforce of the closure spring 28 when the closure trigger 8 is releasedfrom an actuated position.

FIG. 35 is a chart illustrating the dampener effect on a return loadprovided by a return stroke dampener 32. The chart 1000 illustrates thetrigger angle 1002 of the closure trigger 8 plotted against the force1004 applied to the closure trigger 8. As can be seen in FIG. 35, theforce applied by the jaws 22 a, 22 b increases to a maximum point atabout 18 degrees of rotation of the clamp trigger 8. The dampening forcedecreases as the clamp trigger 8 is released and the dampener toggle 78crosses over a center point.

FIG. 21 illustrates the handle assembly 4 after the closure trigger 8has been released and the jaws 22 a, 22 b have assumed an open position.The closure trigger 8 has returned to an unactuated position withrespect to the pistol-grip handle 14. The clamp spring 28 and the rack44 have returned to their respective starting positions. The returnstroke dampener 32 is fully compressed when the clamp spring 28 is in arest position. FIG. 22 illustrates one embodiment of a spring washer 158configured to interface with a rack spring 59 when the rack 44 isadvanced in a distal direction. The spring washer 158 and the rackspring 59 cause the rack 44 to move proximally if the firing trigger 16is released. FIG. 23 illustrates one embodiment of a spring stop 162.The spring stop 162 is coupled to the proximal end of the clamp spring28.

FIG. 24 illustrates one embodiment of an electrical energy system 80mounted within the handle assembly 4. An energy button 18 is configuredto deliver energy to an electrode 92 coupled to the end effector 10. Theenergy button 18 is coupled to a plurality of power activation wires 82.When the energy button 18 is depressed, a circuit is completed allowingdelivery of energy to the electrode 92. A source path 84 couples anelectrical contact mounted on the distal end of the outer tube 23 of theshaft assembly 12. In some embodiments, the source path comprises theouter tube 23. Alternatively, in some embodiments, the source pathcomprises a solid or stranded conductor housed within the outer tube 23.A return path 85 acts as a return for bipolar RF energy delivered to theelectrode. For monopolar RF energy, the return path may comprise agrounding electrode coupled to a patient. In some embodiments, the poweractivation wires 82 are coupled to a generator. The control board 48 isfurther coupled to the jaw position switch 34 and the generator. Thegenerator may prevent delivery of energy to the electrode 92 unless thejaw position sensor 34 indicates that the jaws 22 a, 22 b are in asufficiently closed position.

FIG. 25 illustrates one embodiment of an electrosurgical instrument 202comprising a pre-compressed closure spring 228. The pre-compressedclosure spring 228 comprises a closure spring having a certainpre-compression before actuation of the closure trigger 8. Thepre-compressed closure spring 228 requires a clinician to apply lessforce to a closure trigger 8 to generate the same amount of force at thejaws 22 a, 22 b when compared to an un-compressed spring. Thepre-compressed spring 228 may further provide a shorter stroke forcompressing the jaws 22 a, 22 b to the same closure or force level as anuncompressed spring. The electrosurgical instrument 204 is otherwisesimilar to the electrosurgical instrument 4 discussed with respect toFIGS. 1-24. For example, closure of an end effector coupled to thesurgical instrument 202 is affected by actuating a closure trigger 8 tomove a yoke 226 proximally to compress the pre-compressed spring 228 andtransition the jaws 22 a, 22 b from an open position to a closedposition.

FIG. 26 illustrates one embodiment of surgical instrument 302 comprisinga handle assembly 304 having a top-mounted compound gear 342 and rack344. The firing trigger 316 is coupled to the compound gear 342 by aplurality of teeth 343. Actuation of the firing trigger 316 advances therack 344 in a distal direction. The rack 344 is coupled to a firingactuator (not illustrated) which advances a cutting member distallywithin an end effector coupled to the shaft 312. The surgical instrument302 is otherwise similar to the electrosurgical instrument 4 illustratedin FIGS. 1-24. For example, closure of the jaws of an end effectorcoupled to the shaft assembly 312 is affected by actuating a closuretrigger 8 coupled to a yoke 326 to compress a closure spring 328.

FIGS. 27A and 27B illustrate one embodiment of an electrosurgical endeffector 410 comprising a curved shape. The end effector 410 comprises afirst jaw member 420 a and a second jaw member 420 b. The first jawmember 420 a is pivotally coupled by a pivot pin 479 to the second jawmember 420 b. The electrosurgical end effector 410 is configured to becoupled to an electrosurgical instrument, such as, for example, theelectrosurgical instrument 2 illustrated in FIGS. 1-24. In someembodiments, the first jaw member 420 a and the second jaw member 420 bare smoothly tapered with the proximal portion of the jaw members 420 a,420 b being the widest portion and the distal end of the jaw members 420a, 420 b being the narrowest portion of the jaw members 420 a, 420 b.The smooth taper comprises a taper in a plane of curvature of the endeffector 410 and parallel to a central axis of the shaft 12. Forexample, in some embodiments, the distal portion of the end effector 410may comprise approximately 25% to 50% of the proximal width of the endeffector 410, such as, for example, 33%. The smooth taper providesbetter dissection while maintaining a wide electrode through most of theend effector 410 for better sealing. The first jaw member 420 a and thesecond jaw member 420 b are curved along a longitudinal axis of the endeffector 410. The curve of the end effector 410 comprises a radius ofcurvature. The radius of curvature may comprise, for example, a radiusof about 1.000″ to about 4.000″.

The taper and curvature of the end effector 410 increase visibility ofthe tip 491. The taper compensates for the loss of force on the tissueon more proximal locations of the end effector 410 providing a moreconstant pressure on the tissue. The smooth transitions along thelongitudinal axis of the end effector 410 and the taper distributedeflection along the length of the end effector 410 and reduce stressconcentration allowing greater loads to be applied by the end effector410. The reduced stresses and deflection permit the end effector 410 tobe lengthened beyond non-curved, non-tapered end effectors. For example,in some embodiments, the end effector 410 comprises a length ofapproximately 23 mm.

In some embodiments, the end effector 410 comprises an offset pivot 486.The offset pivot 486 comprises a pivot point offset from thelongitudinal axis of the shaft 12 and the end effector 410. The offsetpivot enables the use of a linkage-style closure mechanism. The link pin488 and offset pivot 486 provides precise control of the movement of thefirst jaw member 420 a. FIG. 28 illustrates one embodiment of an endeffector 510 comprising an offset pivot 586 coupled to an offsetactuator. The offset actuator comprises a single asymmetric lever arm590 coupled to the first jaw member 520 a. The asymmetric lever arm 590provides additional material around the pivot 586 when compared to atraditional two lever arm end effector.

FIG. 29 illustrates one embodiment of an end effector 610 comprising anoffset pivot 686 and an asymmetric lever arm 690 coupled to a shaft 612.The end effector 610 comprises a first jaw member 620 a and a second jawmember 620 b. The first jaw member 620 a is pivotally moveable withrespect to the second jaw member 620 b. The second jaw member 620 b isfixed. The first and second jaw members 620 a, 620 b comprises a curvedshape having a radius of curvature with respect to a longitudinal axisof a shaft 612. The first jaw member 620 a and the second jaw member 620b comprise a smooth taper from the proximal end to the distal end. Thedistal tip comprises a width less than the width of the proximal sectionof the end effector 610. For example, in some embodiments, the distaltip comprises a width of about 25% to about 50% of the width of theproximal section of the end effector 610. The end effector 610 isillustrated in an open position in FIG. 29. In some embodiments,movement of the first jaw member 620 a with respect to the second jawmember 620 b is accomplished by a linked connection between theasymmetric lever arm 690 and an outer sheath 623 of the shaft 612. A lowfriction bushing 698, such as, for example, a lubricious metal orplastic, comprises a sliding interface between the asymmetric lever arm690 and the outer sheath 623. The low friction bushing 698 is disposedbetween an outer diameter of the asymmetric lever arm 690 and an innerdiameter of the shaft 612. FIG. 30 illustrates the end effector 610 ofFIG. 29 in a closed position. As shown in FIG. 30, the end effector 610is transitioned to a closed position by moving the asymmetric lever arm690 proximally. Proximal movement of the asymmetric lever arm 690 may beaffected by, for example, actuating a closure trigger 8 of a handleassembly 4 coupled to the end effector 610 by the shaft 612.

In some embodiments, an electrode 692 is coupled to the second jawmember 620 b. The electrode 692 is adhered to the second jaw member 620b by an adhesive, such as, for example, a silicon or epoxy adhesive. Theelectrode 692 is selectively coated with a ceramic coating that provideselectrical insulation to prevent shorting between the electrode 692 andthe second jaw member 620 b. In some embodiments, the ceramic coatingand adhesive comprise a thermal conductivity of about 0.5 W/(mK) toabout 2.0 W/(mK). The electrode 692 contacts a source electrode on thedistal end of the outer tube 623 when the first jaw member 620 a isrotated into a closed position with respect to the second jaw member 620b. Placement of the contact electrode on the outer shaft 623 ensures agood connection between the electrode 692 and an energy source. In someembodiments, the first jaw member 620 a and/or the second jaw member 620b define a cutting member slot. FIG. 31 illustrates one embodiment ofthe second jaw member 620 b comprising a cutting member slot 696. Theproximal end of the cutting member slot 696 begins in a plane through acentral axis of the shaft 612. The cutting member slot 696 biases to afirst side of the central axis of the shaft 612 then crosses the centralaxis to a location biased to the opposite side of the central axis atthe distal-most portion of the cutting member slot 696. The cuttingmember slot 696 shape maximizes the radius of the cutting member slot696 reducing the bending load on the cutting member 695. The geometry ofthe cutting member slot 696 maintains a nearly equivalent electrode 692width on both sides of the cutting member slot 696. In some embodiments,the curvature of the cutting member slot 696 is substantially equal tothe curvature of the end effector 610, which is substantially equal tothe curvature of the anatomy being transected. In some embodiments, aradius of curvature of the cutting member slot 696 varies from about2.000″ to about 4.000″ over the length of the cutting member slot 696.In some embodiments, the cutting member slot 696 is biased to either thefirst side and/or the second side of the central axis of the shaft 612by a distance of greater than 0.000″ to a maximum of about 0.065″.

While the examples herein are described mainly in the context ofelectrosurgical instruments, it should be understood that the teachingsherein may be readily applied to a variety of other types of medicalinstruments. By way of example only, the teachings herein may be readilyapplied to tissue graspers, tissue retrieval pouch deployinginstruments, surgical staplers, ultrasonic surgical instruments, etc. Itshould also be understood that the teachings herein may be readilyapplied to any of the instruments described in any of the referencescited herein, such that the teachings herein may be readily combinedwith the teachings of any of the references cited herein in numerousways. Other types of instruments into which the teachings herein may beincorporated will be apparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

The disclosed embodiments have application in conventional endoscopicand open surgical instrumentation as well as application inrobotic-assisted surgery.

Embodiments of the devices disclosed herein can be designed to bedisposed of after a single use, or they can be designed to be usedmultiple times. Embodiments may, in either or both cases, bereconditioned for reuse after at least one use. Reconditioning mayinclude any combination of the steps of disassembly of the device,followed by cleaning or replacement of particular pieces, and subsequentreassembly. In particular, embodiments of the device may bedisassembled, and any number of the particular pieces or parts of thedevice may be selectively replaced or removed in any combination. Uponcleaning and/or replacement of particular parts, embodiments of thedevice may be reassembled for subsequent use either at a reconditioningfacility, or by a surgical team immediately prior to a surgicalprocedure. Those skilled in the art will appreciate that reconditioningof a device may utilize a variety of techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of the presentapplication.

By way of example only, embodiments described herein may be processedbefore surgery. First, a new or used instrument may be obtained and ifnecessary cleaned. The instrument may then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK bag. The container and instrumentmay then be placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation may kill bacteria on the instrument and in the container.The sterilized instrument may then be stored in the sterile container.The sealed container may keep the instrument sterile until it is openedin a medical facility. A device may also be sterilized using any othertechnique known in the art, including but not limited to beta or gammaradiation, ethylene oxide, or steam.

It is worthy to note that any reference to “one aspect,” “an aspect,”“one embodiment,” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the aspect isincluded in at least one aspect. Thus, appearances of the phrases “inone aspect,” “in an aspect,” “in one embodiment,” or “in an embodiment”in various places throughout the specification are not necessarily allreferring to the same aspect. Furthermore, the particular features,structures or

One skilled in the art will recognize that the herein describedcomponents (e.g., operations), devices, objects, and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific exemplars set forth and theaccompanying discussion are intended to be representative of their moregeneral classes. In general, use of any specific exemplar is intended tobe representative of its class, and the non-inclusion of specificcomponents (e.g., operations), devices, and objects should not be takenlimiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely examples and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

Some aspects may be described using the expression “coupled” and“connected” along with their derivatives. It should be understood thatthese terms are not intended as synonyms for each other. For example,some aspects may be described using the term “connected” to indicatethat two or more elements are in direct physical or electrical contactwith each other. In another example, some aspects may be described usingthe term “coupled” to indicate that two or more elements are in directphysical or electrical contact. The term “coupled,” however, also maymean that two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

In some instances, one or more components may be referred to herein as“configured to,” “configurable to,” “operable/operative to,”“adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Thoseskilled in the art will recognize that “configured to” can generallyencompass active-state components and/or inactive-state componentsand/or standby-state components, unless context requires otherwise.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true scope of the subject matter described herein. It will beunderstood by those within the art that, in general, terms used herein,and especially in the appended claims (e.g., bodies of the appendedclaims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitationis explicitly recited, those skilled in the art will recognize that suchrecitation should typically be interpreted to mean at least the recitednumber (e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that typically a disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Also, although various operational flows are presented in asequence(s), it should be understood that the various operations may beperformed in other orders than those which are illustrated, or may beperformed concurrently. Examples of such alternate orderings may includeoverlapping, interleaved, interrupted, reordered, incremental,preparatory, supplemental, simultaneous, reverse, or other variantorderings, unless context dictates otherwise. Furthermore, terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

In summary, numerous benefits have been described which result fromemploying the concepts described herein. The foregoing description ofthe one or more embodiments has been presented for purposes ofillustration and description. It is not intended to be exhaustive orlimiting to the precise form disclosed. Modifications or variations arepossible in light of the above teachings. The one or more embodimentswere chosen and described in order to illustrate principles andpractical application to thereby enable one of ordinary skill in the artto utilize the various embodiments and with various modifications as aresuited to the particular use contemplated. It is intended that theclaims submitted herewith define the overall scope.

Various aspects of the subject matter described herein are set out inthe following numbered clauses:

1. A surgical instrument comprising: a handle; a shaft assemblyextending distally from the handle; an end effector coupled to a distalend of the shaft assembly, wherein the end effector comprises: a jawassembly having a proximal end and a distal end, the jaw assemblycomprising: a moveable jaw member; and a fixed jaw member, wherein themoveable jaw member is pivotably moveable between an open position and aclosed position with respect to the fixed jaw member; wherein in theclosed position, the jaw assembly defines a radius of curvature and asmooth taper from the proximal end to the distal end.

2. The surgical instrument of clause 1, wherein the distal end of thejaw assembly defines a width of between about 25% to about 50% of awidth of a proximal end of the jaw assembly.

3. The surgical instrument of clause 2, wherein the smooth taper isconfigured to provide nearly constant pressure from a proximal end to adistal end of the jaw assembly.

4. The surgical instrument of clause 1, wherein the radius of curvatureis about 1.000″ to about 4.000″.

5. The surgical instrument of clause 1, comprising a cutting memberlongitudinally deployable within a longitudinal curved slot defined bythe jaw assembly, wherein the longitudinal curved slot comprises aproximal portion substantially in-line with a central axis of the shaftassembly, and wherein the longitudinal curved slot substantially followsthe radius of curvature of the jaw assembly.

6. The surgical instrument of clause 5, wherein a central portion of thelongitudinal curved slot is offset on a first side of the central axisof the shaft assembly by a distance of greater than 0.000″ to about0.065″.

7. The surgical instrument of clause 6, wherein a distal portion of thelongitudinal curved slot is offset on a second side of the central axisof the shaft assembly by a distance of greater than 0.000″ to about0.065″.

8. The surgical instrument of clause 7, wherein the radius of curvaturevaries from about 2.000″ to about 4.000″.

9. The surgical instrument of clause 1, comprising a lever armasymmetrically coupled to the moveable jaw member on a first side of acentral axis of the shaft assembly, wherein the lever arm is configuredto pivot the moveable jaw member from an open position to a closedposition.

10. The surgical instrument of clause 9, wherein a pivot connectionbetween the moveable jaw member and the fixed jaw member is offset tothe first side of the axis of the shaft assembly.

11. The surgical instrument of clause 10, wherein the pivot connectioncomprises a pinned link-slider.

12. The surgical instrument of clause 9, wherein the lever arm extendslongitudinally through the shaft assembly, and wherein a lubricousbushing is located between an outer diameter of the lever arm and aninner diameter of the shaft assembly.

13. The surgical instrument of clause 12, wherein the lubricous bushingcomprises a plastic material.

14. The surgical instrument of clause 12, wherein the lubricous bushingcomprises a dissimilar metal material.

15. The surgical instrument of clause 1, comprising an electrodedisposed on the fixed jaw member, wherein the electrode is configured todeliver an electrosurgical radiofrequency (RF) signal.

16. The surgical instrument of clause 15, comprising a ceramic coatingdisposed on the electrode to electrically isolate the electrode from thefixed jaw member.

17. The surgical instrument of clause 16, wherein the ceramic coatingcomprises one of aluminum oxide or zirconium oxide.

18. The surgical instrument of clause 15, wherein the electrode iscoupled to the fixed jaw member by an adhesive.

19. The surgical instrument of clause 18, wherein a thermal conductivityof the adhesive is approximately 0.5 W/(mK) to 2.0 W/(mK).

20. A surgical end effector, comprising: a jaw assembly having aproximal end and a distal end, the jaw assembly comprising: a moveablejaw member; a fixed jaw member; and a pivot connection coupling themoveable jaw member and the fixed jaw member, wherein the moveable jawmember is pivotably moveable between an open position and a closedposition with respect to the fixed jaw member; wherein, in the closedposition, the jaw assembly defines a radius of curvature and a smoothtaper from the proximal end to the distal end.

21. The surgical end effector of clause 20, comprising a lever armasymmetrically coupled to the first jaw member on a first side of acentral axis of the jaw assembly, wherein the lever arm is configured topivot the moveable jaw member from the open position to the closedposition.

22. The surgical end effector of clause 21, wherein the pivot connectionbetween the moveable jaw member and the fixed jaw member is offset tothe first side of the axis of the jaw assembly.

23. The surgical end effector of clause 22, wherein the pivot connectioncomprises a pinned link-slider.

24. The surgical end effector of clause 21, comprising a lubricousbushing, wherein the lubricous bushing is configured to be locatedbetween an outer diameter of the lever arm and an inner diameter of anouter shaft when the end effector is coupled to a surgical instrument.

25. The surgical end effector of clause 24, wherein the lubricousbushing comprises a plastic material.

26. The surgical end effector of clause 24, wherein the lubricousbushing comprises a dissimilar metal material.

27. A surgical instrument comprising: a handle; a shaft assemblyextending distally from the handle, the shaft assembly comprising alever arm extending distally therethrough; an end effector coupled to adistal end of the shaft assembly, wherein the end effector comprises: ajaw assembly having a proximal end and a distal end, the jaw assemblycomprising: a moveable jaw member; and a fixed jaw member, wherein themoveable jaw member is pivotably moveable between an open position and aclosed position with respect to the fixed jaw member, wherein the leverarm is asymmetrically coupled to the moveable jaw member on a first sideof a central axis of the shaft assembly, and wherein a pivot connectionbetween the moveable jaw member and the fixed jaw member is offset tothe first side of the central axis of the shaft assembly; wherein in theclosed position, the jaw assembly defines a radius of curvature and asmooth taper from the proximal end to the distal end.

28. A surgical instrument comprising: a handle assembly comprising: aclosure trigger defining an energy button hole; an energy button locatedwithin the energy button hole; a firing trigger; and a shaft assemblycoupled to the handle assembly, the shaft assembly comprising: an outertube; a closure actuator operatively coupled to the closure trigger; anda firing actuator operatively coupled to the firing trigger; and an endeffector coupled to a distal end of the shaft assembly, the end effectorcomprising: a jaw assembly having a proximal end and a distal end, thejaw assembly comprising: a first jaw member; a second jaw member,wherein the first and second jaw members define a longitudinal slot,wherein the closure actuator is coupled to the first jaw member topivotally move the first jaw member from an open position to a closedposition relative to the second jaw member; and a cutting memberdeployable within the longitudinal slot, wherein the cutting member iscoupled to the firing actuator to advance the cutting member distallywithin the longitudinal slot.

29. The surgical instrument of clause 28, wherein the handle assemblycomprises: a compound gear coupled to the firing trigger, the compoundgear comprising a high pivot; and a rack coupled to the firing actuatorand operably coupled to the compound gear, wherein the compound gear isconfigured to rotate upon actuation of the firing trigger to advance therack and firing actuator distally to deploy the cutting member distallywithin the end effector.

30. The surgical instrument of clause 29, wherein the firing actuatorcomprises a pull tube.

31. The surgical instrument of clause 29, wherein the handle assemblycomprises a firing lock configured to prevent actuation of the firingtrigger prior to closure of the jaw assembly, wherein the closuretrigger is configured to release the firing lock when the closuretrigger is in a predetermined closure position, and wherein release ofthe firing lock allows actuation of the firing trigger.

32. The surgical instrument of clause 31, wherein the handle assemblycomprises a cutting member return spring stop comprising a crimp and awasher.

33. The surgical instrument of clause 28, wherein the closure triggercomprises a yoke interfaced with a closure spring, wherein the closurespring is coupled to the closure actuator, wherein actuation of theclosure trigger slides the yoke proximally to compress the closurespring, and wherein compression of the closure spring moves the closureactuator proximally to rotate the first jaw member into a closedposition.

34. The surgical instrument of clause 33, wherein the jaw closure springcomprises a pre-compressed spring.

35. The surgical instrument of clause 28, wherein the closure actuatorcomprises a lever arm asymmetrically coupled to the first jaw member,and wherein the jaw assembly comprises an offset pivot.

36. The surgical instrument of clause 28, wherein the shaft assemblycomprises an electrical contact disposed on the outer tube and the endeffector comprises an electrode, wherein the electrical contact isconfigured electrically couple the electrode to an energy source whenthe jaw assembly is in a closed position.

37. The surgical instrument of clause 1, wherein in the closed position,the jaw assembly defines a radius of curvature and a smooth taper fromthe proximal end to the distal end.

38. A surgical instrument comprising: a handle assembly comprising: aclosure trigger defining an energy button hole; an energy button locatedwithin the energy button hole; and a firing trigger; a shaft assemblycoupled to the handle assembly, the shaft assembly comprising: an outertube; a closure actuator operatively coupled to the closure trigger; anda firing actuator operatively coupled to the firing trigger; and an endeffector coupled to a distal end of the shaft assembly, the end effectorcomprising: a jaw assembly having a proximal end and a distal end, thejaw assembly comprising: a moveable jaw member; a fixed jaw member,wherein the moveable jaw member is pivotably moveable between an openposition and a closed position with respect to the fixed jaw member, andwherein in the closed position, the jaw assembly defines a radius ofcurvature; and a cutting member deployable within the curved slot,wherein the cutting member is coupled to the firing actuator to advancethe cutting member distally within the curved slot.

39. The surgical instrument of clause 38, wherein the handle assemblycomprises: a compound gear coupled to the firing trigger, the compoundgear comprising a high pivot; and a rack coupled to the firing actuatorand operably coupled to the compound gear, wherein the compound gear isconfigured to rotate upon actuation of the firing trigger to advance therack and firing actuator distally to deploy the cutting member distallywithin the end effector.

40. The surgical instrument of clause 38, wherein the firing actuatorcomprises a pull tube.

41. The surgical instrument of clause 40, wherein the handle assemblycomprises a firing lock configured to prevent actuation of the firingtrigger prior to closure of the jaw assembly, wherein the closuretrigger is configured to release the firing lock when the closuretrigger is in a predetermined closure position, and wherein release ofthe firing lock allows actuation of the firing trigger.

42. The surgical instrument of clause 41, wherein the handle assemblycomprises a cutting member return spring stop comprising a crimp and awasher.

43. The surgical instrument of clause 38, wherein the closure triggercomprises a yoke interfaced with a closure spring, wherein the closurespring is coupled to the closure actuator, wherein actuation of theclosure trigger slides the yoke proximally to compress the closurespring, and wherein compression of the closure spring moves the closureactuator proximally to rotate the first jaw member into a closedposition.

44. The surgical instrument of clause 43, wherein the jaw closure springcomprises a pre-compressed spring.

45. The surgical instrument of clause 38, wherein the shaft assemblycomprises an electrical contact disposed on the outer tube and the endeffector comprises an electrode, wherein the electrical contact isconfigured electrically couple to the end effector when the jaw assemblyis in a closed position.

46. The surgical instrument of clause 38, wherein in the closed positionthe jaw assembly comprising smooth taper from the proximal end to thedistal end.

47. A surgical instrument comprising: a handle assembly comprising: aclosure trigger defining an energy button hole; an energy button locatedwithin the energy button hole; and a firing trigger; a shaft assemblycoupled to the handle assembly, the shaft assembly comprising: an outertube; a closure actuator operatively coupled to the closure trigger; anda firing actuator operatively coupled to the firing trigger; and an endeffector coupled to a distal end of the shaft assembly, the end effectorcomprising: a jaw assembly having a proximal end and a distal end, thejaw assembly comprising: a moveable jaw member; and a fixed jaw member,wherein the moveable jaw member is pivotably moveable between an openposition and a closed position with respect to the fixed jaw member,wherein the closure actuator is asymmetrically coupled to the moveablejaw member on a first side of a central axis of the shaft assembly, andwherein a pivot connection between the moveable jaw member and the fixedjaw member is offset to the first side of the central axis of the shaftassembly; wherein in the closed position, the jaw assembly defines aradius of curvature and a smooth taper from the proximal end to thedistal end.

What is claimed is:
 1. A surgical instrument comprising: a handle; ashaft assembly extending distally from the handle, wherein the shaftassembly defines a central axis, and wherein the shaft assembly definesan outer circumference; and an end effector coupled to a distal end ofthe shaft assembly, wherein the end effector comprises: a jaw assembly,comprising: a proximal end; a distal end; and a curved body extendingfrom the proximal end to the distal end of the jaw assembly, the curvedbody comprising: a moveable jaw member extending from the proximal endto the distal end of the jaw assembly; and a fixed jaw member extendingfrom the proximal end to the distal end of the jaw assembly, wherein themoveable jaw member is pivotably moveable between an open position and aclosed position with respect to the fixed jaw member; wherein, in theclosed position, the curved body defines a radius of curvature and asmooth taper along the curved body from the proximal end to the distalend of the jaw assembly, wherein the curved body is contained within acylindrical volume defined by the outer circumference of the shaftassembly and extending distally from the shaft assembly along thecentral axis, and wherein the central axis of the shaft assemblycomprises a first side and a second side; and a cutting memberlongitudinally deployable within a longitudinal curved slot defined bythe jaw assembly, wherein the longitudinal curved slot comprises aproximal portion substantially in-line with the central axis of theshaft assembly, and wherein the longitudinal curved slot substantiallyfollows the radius of curvature of the curved body.
 2. The surgicalinstrument of claim 1, wherein the distal end of the jaw assemblydefines a width of between about 25% to about 50% of a width of theproximal end of the jaw assembly.
 3. The surgical instrument of claim 2,wherein the smooth taper is configured to provide nearly constantpressure from the proximal end to the distal end of the jaw assembly. 4.The surgical instrument of claim 1, wherein the radius of curvature isabout 1.000″ to about 4.000″.
 5. The surgical instrument of claim 1,wherein a central portion of the longitudinal curved slot is offset onthe first side of the central axis of the shaft assembly by a distanceof greater than 0.000″ to about 0.065″, and wherein the central portionis defined between a first central-portion wall on the first side of thecentral axis and a second central-portion wall on the first side of thecentral axis.
 6. The surgical instrument of claim 5, wherein a distalportion of the longitudinal curved slot is offset on the second side ofthe central axis of the shaft assembly by a distance of greater than0.000″ to about 0.065″, and wherein the distal portion is definedbetween a first distal-portion wall on the second side of the centralaxis and a second distal-portion wall on the second side of the centralaxis.
 7. The surgical instrument of claim 6, wherein the radius ofcurvature varies from about 2.000″ to about 4.000″.
 8. The surgicalinstrument of claim 1, comprising a lever arm asymmetrically coupled tothe moveable jaw member on the second side of the central axis of theshaft assembly, wherein the lever arm is configured to pivot themoveable jaw member from the open position to the closed position. 9.The surgical instrument of claim 8, wherein a pivot connection betweenthe moveable jaw member and the fixed jaw member is offset to the secondside of the central axis of the shaft assembly.
 10. The surgicalinstrument of claim 9, wherein the pivot connection comprises a pinnedlink-slider.
 11. The surgical instrument of claim 8, wherein the leverarm extends longitudinally through the shaft assembly, and wherein alubricous bushing is located between an outer diameter of the lever armand an inner diameter of the shaft assembly.
 12. The surgical instrumentof claim 11, wherein the lubricous bushing comprises a plastic material.13. The surgical instrument of claim 11, wherein the lubricous bushingcomprises a dissimilar metal material.
 14. The surgical instrument ofclaim 1, comprising an electrode disposed on the fixed jaw member,wherein the electrode is configured to deliver an electrosurgicalradiofrequency (RF) signal.
 15. The surgical instrument of claim 14,comprising a ceramic coating disposed on the electrode to electricallyisolate the electrode from the fixed jaw member.
 16. The surgicalinstrument of claim 15, wherein the ceramic coating comprises one ofaluminum oxide or zirconium oxide.
 17. The surgical instrument of claim14, wherein the electrode is coupled to the fixed jaw member by anadhesive.
 18. The surgical instrument of claim 17, wherein a thermalconductivity of the adhesive is approximately .5 W/(mK) to 2.0 W/(mK).19. A surgical end effector extending distally from a shaft defining acentral axis, the surgical end effector comprising: a jaw assembly,comprising: a proximal end; a distal end; a longitudinal slot,comprising a length extending between the proximal end and the distalend of the jaw assembly, wherein the longitudinal slot comprises: aproximal portion defined between a first proximal-portion wall and asecond proximal-portion wall, wherein the central axis extends betweenthe first proximal-portion wall and the second proximal-portion wall; anintermediate portion extending distally from the proximal portion,wherein the intermediate portion is defined between a firstintermediate-portion wall and a second intermediate-portion wall, andwherein the first intermediate-portion wall and the secondintermediate-portion wall extend on a first side of the central axis;and a distal portion extending distally from the intermediate portion,wherein the distal portion is defined between a first distal-portionwall and a second distal-portion wall, and wherein the firstdistal-portion wall and the second distal-portion wall extend on asecond side of the central axis; a moveable jaw member; a fixed jawmember; and a pivot connection coupling the moveable jaw member and thefixed jaw member, wherein the moveable jaw member is pivotably moveablebetween an open position and a closed position with respect to the fixedjaw member; and wherein, in the closed position, the jaw assemblycomprises a curvature along the length of the longitudinal slot, andwherein the jaw assembly is gradually tapered along the length of thelongitudinal slot; and wherein the surgical end effector comprises alever arm asymmetrically coupled to the movable jaw member on the secondside of the central axis, wherein the lever arm is configured to pivotthe moveable jaw member from the open position to the closed position.20. The surgical end effector of claim 19, wherein the pivot connectionbetween the moveable jaw member and the fixed jaw member is offset tothe second side of the central axis.
 21. The surgical end effector ofclaim 20, wherein the pivot connection comprises a pinned link-slider.22. The surgical end effector of claim 19, comprising a lubricousbushing, wherein the lubricous bushing is configured to be locatedbetween an outer diameter of the lever arm and an inner diameter of anouter shaft when the end effector is coupled to a surgical instrument.23. The surgical end effector of claim 22, wherein the lubricous bushingcomprises a plastic material.
 24. The surgical end effector of claim 22,wherein the lubricous bushing comprises a dissimilar metal material. 25.A surgical instrument, comprising: a shaft assembly defining an outerperimeter and a central axis extending therethrough; and an end effectorextending distally from the shaft assembly, wherein the end effectorcomprises: an arcuate jaw assembly confined by a volume defined alongthe central axis and bound by the outer perimeter defined by the shaftassembly, wherein the arcuate jaw assembly comprises: an arcuate body; aslot extending through the arcuate body, wherein the slot is configuredto receive a cutting member, and wherein the slot comprises: a proximalportion defined between a first proximal-portion wall and a secondproximal-portion wall, wherein the central axis extends between thefirst proximal-portion wall and the second proximal-portion wall; anintermediate portion extending distally from the proximal portion,wherein the intermediate portion is defined between a firstintermediate-portion wall and a second intermediate-portion wall, andwherein the first intermediate-portion wall and the secondintermediate-portion wall extend on a first side of the central axis;and a distal portion extending distally from the intermediate portion,wherein the distal portion is defined between a first distal-portionwall and a second distal-portion wall, and wherein the firstdistal-portion wall and the second distal-portion wall extend on asecond side of the central axis; a moveable jaw member; and a fixed jawmember, wherein the moveable jaw member is moveable between an openposition and a closed position with respect to the fixed jaw member; anda lever arm asymmetrically coupled to the moveable jaw member on thesecond side of the central axis of the shaft assembly, wherein the leverarm is configured to pivot the moveable jaw member from the openposition to the closed position.
 26. A surgical instrument comprising: ahandle; a shaft assembly extending distally from the handle, the shaftassembly comprising a lever arm, and wherein the shaft assembly definesa central axis extending therethrough, and wherein the shaft assemblydefines an outer circumference; and an end effector coupled to a distalend of the shaft assembly, wherein the end effector comprises: a jawassembly, comprising: a proximal end; a distal end; an arcuate portionbetween the proximal end and the distal end; a moveable jaw member; anda fixed jaw member, wherein the moveable jaw member is pivotablymoveable between an open position and a closed position with respect tothe fixed jaw member, wherein the lever arm is asymmetrically coupled tothe moveable jaw member on a first side of the central axis of the shaftassembly, and wherein a pivot connection between the moveable jaw memberand the fixed jaw member is offset to the first side of the central axisof the shaft assembly; wherein, in the closed position, the jaw assemblyis uninterruptedly tapered along the arcuate portion, and wherein thearcuate portion is confined by a cylindrical volume comprising acircumference substantially equal to the outer circumference of theshaft assembly and extending distally from the shaft assembly along thecentral axis; and wherein the jaw assembly defines a longitudinal curvedslot, wherein a cutting member is longitudinally deployable within thelongitudinal curved slot, wherein the longitudinal curved slot comprisesa proximal portion substantially in-line with the central axis of theshaft assembly, and wherein the longitudinal curved slot substantiallyfollows a radius of curvature of the arcuate portion.